How to Replace a Bosch Washing Machine Drain Pump
A Bosch front-loader throwing an E18 drain fault, leaving water after a cycle, or grinding at the bottom-left usually needs a new drain pump. Drain the filter, twist out the bayonet-mount pump, and swap it in 25-40 minutes. BSH 00145787 fits most models. Difficulty: intermediate.
The E18 code means the machine could not drain in time, and on Bosch washers that traces to the drain pump behind the bottom-left service flap. A pump fails when its impeller jams on debris or the motor bearing wears, and a filter packed with coins and lint often tells the story. Confirm it is the pump and not a downstream blockage, then work from below where the pump sits exposed.
Tools & parts#
| Item | Detail |
|---|---|
| Torx T20 | if removing panels |
| Flathead screwdriver, pliers | clamps and connectors |
| Shallow pan, towels | catching residual water |
| Part | drain pump BSH 00145787 |
Do You Have the Right Tools?
Bearing puller set ($120), drum spider wrench ($85), multimeter ($85), and diagnostic software. Our technician arrives with $3,000+ in professional tools — your diagnostic is free.
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Safety first#
Disconnect power and water. Drain all water from filter area first. The pump area retains water.
Step-by-step#
Step 1: Drain the residual water#
Open the bottom-left service flap and run the small drain hose into a container. Then slowly unscrew the filter cap counterclockwise to release the rest (expect 200-500ml), remove it, and clear any debris from the housing. Wear gloves, since the standing water is often dirty, and inspect what you pull out — coins, buttons, and fabric scraps are exactly what jam these pumps.
Step 2: Access the pump#
The easiest route is from below — lay the machine carefully on its back and the pump is visible at the base with no panel removal. Alternatively, take off the bottom kick plate; on some models the pump connections are reachable that way.
Step 3: Disconnect the old pump#
Unplug the 2-pin motor connector (press the tab and pull), then release both hoses by squeezing their spring clamps with pliers, sliding them back, and pulling the hoses off — keep towels ready. Most Bosch pumps use a bayonet mount: twist the housing counterclockwise about 30 degrees until it releases and pull it out. Some models instead use 2-3 Torx T20 screws. With the old pump out, spin the impeller by hand — if it barely turns, grinds, or has a cracked blade, the pump is confirmed bad rather than merely blocked.
Step 4: Install the new pump#
Transfer the filter cap if the new pump does not include one, and check that its O-ring is intact so it will not weep later. Seat the pump in the bayonet mount and twist clockwise until it locks (or screw it in), then reconnect both hoses firmly and slide the spring clamps back into position. Confirm the new impeller spins freely, then reconnect the electrical connector.
Step 5: Test#
Stand the machine upright, restore water and power, and run a Rinse + Spin. During the drain phase you should hear a steady hum, not grinding or clicking; confirm E18 clears and check every connection for leaks. If the drain runs clean and no water remains at the end of the cycle, the pump swap is complete.
Safety First — Know the Risks
High-voltage components and pressurized water lines create flood and shock risk. A single loose fitting can cause thousands in water damage. Our techs are licensed and insured — let them handle the risk.
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Troubleshooting#
| Symptom | Likely cause |
|---|---|
| E18 persists | a hose clamp not engaged (air leak), or a drain hose higher than 39 inches above the floor |
| Pump runs but no water drains | a blockage in the drain hose, not the pump |
| New pump clicks | a shipping protector still installed, or debris that fell in during install |
| Slow drain | a worn filter-cap O-ring from the old-cap transfer |
When to call a pro#
Get help if E18 persists after a pump swap with the drain hose verified clear (a control-board issue), if prolonged E18 caused water damage to nearby electrical parts, or if the pump housing in the tub is cracked where the bayonet mounts.
Appliance Repair Technician · 11 years experience
Experienced technician with 11 years specializing in Frigidaire and Electrolux refrigerator and dryer repair with a focus on safety.
